Field of the Invention
The present disclosure relates to resource allocation. In particular, but not exclusively, the present disclosure relates to allocation of finite resources to network nodes in a network.
Description of the Related Technology
Known session border controllers (SBCs), such as Metaswitch™'s Perimeta™, have various user configurable limits in place regulating admission of new calls to a network or system. For example, “There may only be 10,000 calls up at one time on SBC A” or “A maximum of 500 calls per second can be accepted to destination X”. The process of policing these limits is called call admission control (CAC). With just one session border controller, determining whether to accept or reject a call based on such limits is relatively straightforward.
With multiple SBCs, determining whether to accept or reject a call based on such limits is difficult as globally configured CAC limits are policed across a plurality of network nodes (for example across a cluster of network nodes). For example, “There may only be 10,000 calls up at one time summed across all SBCs in cluster A” or “A maximum of 500 calls per second can be accepted to destination X, regardless of which SBCs in cluster A they came through”.
In a fixed deployment, the above scenario could be tackled by dividing the limit by the number of instances (for example if there are N SBCs, then each SBC could be apportioned 1/Nth of the available limit). This however falls short in a cloud environment, where there is an ever changing number of SBCs acting as a single entity (i.e. N both rapidly varies with time and at any given time is unknown to each SBC).